Bon Appetit Shrimp and Potato Salad

Bon Appetit Shrimp and Potato Salad

1 small red onion (about 4 oz.), thinly sliced into rings
5 Tbsp. red wine vinegar
1 3/4 lb. unpeeled russet potatoes
Kosher salt
1/4 cup dry white wine
Freshly ground black pepper
1 pound large shrimp, cooked, peeled, and deveined, cut into 3/4" pieces
3 plum tomatoes (about 2/3 lb.), quartered lengthwise, then crosswise
5 Tbsp. extra-virgin olive oil
6 fresh basil leaves, thinly sliced

Preparation
Place sliced onion in a strainer and rinse under cold water for 20 seconds; drain. Transfer onion to a large bowl; add vinegar and toss to coat. Set aside.
Meanwhile, boil potatoes in a medium pot of lightly salted water until tender, about 45 minutes. Drain. Let cool slightly. Using a kitchen towel, rub skins off potatoes. Cut potatoes into 3/4" pieces and transfer to a medium bowl; drizzle wine over. Season with salt and pepper and gently toss to combine; set aside.
Add shrimp, tomatoes, and oil to bowl with onions. Season with salt and pepper and toss gently to incorporate. Let sit for 5 minutes until flavors meld. Add basil, toss gently, and serve.